Overhead door drop stop

Abstract

The present invention is a door drop stop system designed to require a minimal amount of time and modification to install in an existing door system. It is effective with all overhead doors which employ a central axle; such overhead doors are in widespread use in residential, commercial, and vehicular applications. In addition, other configurations of the door drop stop system are effective with slab doors, bifold doors, and rollup doors. The present invention will reduce or eliminate property damage and personal injury resulting from a failure of a component of the door or its counterbalance system.

VI. What is claimed is: 
 I. A door drop stop system comprising:  
 a rewind box,  
 mounting means, and  
 vertical and horizontal braces.  
 
     
     
         2 . A door drop stop system according to claim  1  wherein said rewind box comprises a commercially available inertia reel and a length of strap.  
     
     
         3 . A door drop stop system according to claim  1  wherein said mounting means comprise a mounting lug to provide a solid anchor for said rewind box to be mounted to a fixed structure near the existing door.  
     
     
         4 . A door drop stop system according to claim  1  wherein said mounting means includes selected mechanical fasteners depending upon the nature of the structure to which it is mounted.  
     
     
         5 . A door drop stop system according to claim  1  wherein said mounting means comprises mechanical fasteners and at least one bracket attached to the door, said bracket preventing damage to the door.  
     
     
         6 . A door drop stop system according to  claim 2  wherein said inertia reel allows normal motion, but will lock as soon as a predetermined rate of rotation is reached due to the door begining to free fall.  
     
     
         7 . A door drop stop system according to  claim 2  wherein said inertia reel has sufficient strength to arrest the downward motion of the falling door upon which it is mounted.  
     
     
         8 . A door drop stop system according to  claim 2  wherein said strap is made of strong material which will withstand forces applied to it during inertia reel lockup.  
     
     
         9 . A door drop stop system according to  claim 2  wherein said length of strap is of sufficient length to permit full opening and closing of the door.  
     
     
         10 . A door drop stop system according to claim  1  adapted to be applied to overhead doors.  
     
     
         11 . A door drop stop system according to  claim 10  wherein said door drop stop system is mounted to a fixed structure and to the overhead door.  
     
     
         12 . A door drop stop system according to claim  1  wherein said vertical and horizontal braces are mounted to overhead structure to provide a safe means of catching said overhead door in the event it would fall out of its tracks while in the open position.  
     
     
         13 . A door drop stop system according to claim  1  adapted to be applied to high lift doors.  
     
     
         14 . A door drop stop system according to claim  1  adapted to be applied to slab doors.  
     
     
         15 . A door drop stop system according to claim  1  adapted to be applied to bifold doors.  
     
     
         16 . A door drop stop system according to claim  1  adapted to be applied to rollup doors.  
     
     
         17 . A door drop stop system according to  claim 16  for rollup doors wherein said strap is mounted to a shaft which is an integral part of said rollup door.  
     
     
         18 . A door drop stop system according to  claim 8  wherein said strap is made of nylon.